package org.apache.lucene.demo;

/**
 * Copyright 2004 The Apache Software Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.index.IndexWriter;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Date;

/** Index all text files under a directory. */
public class IndexFiles {

    private IndexFiles() {
    }

    static final File INDEX_DIR = new File("index");

    /** Index all text files under a directory. */
    public static void main(String[] args) {
        String usage = "java org.apache.lucene.demo.IndexFiles <root_directory>";
        if (args.length == 0) {
            System.err.println("Usage: " + usage);
            System.exit(1);
        }

        if (INDEX_DIR.exists()) {
            System.out.println("Cannot save index to '" + INDEX_DIR + "' directory, please delete it first");
            System.exit(1);
        }

        final File docDir = new File(args[0]);
        if (!docDir.exists() || !docDir.canRead()) {
            System.out.println("Document directory '" + docDir.getAbsolutePath() + "' does not exist or is not readable, please check the path");
            System.exit(1);
        }

        Date start = new Date();
        try {
            IndexWriter writer = new IndexWriter(INDEX_DIR, new StandardAnalyzer(), true);
            System.out.println("Indexing to directory '" + INDEX_DIR + "'...");
            indexDocs(writer, docDir);
            System.out.println("Optimizing...");
            writer.optimize();
            writer.close();

            Date end = new Date();
            System.out.println(end.getTime() - start.getTime() + " total milliseconds");

        } catch (IOException e) {
            System.out.println(" caught a " + e.getClass() + "\n with message: " + e.getMessage());
        }
    }

    static void indexDocs(IndexWriter writer, File file) throws IOException {
        // do not try to index files that cannot be read
        if (file.canRead()) {
            if (file.isDirectory()) {
                String[] files = file.list();
                // an IO error could occur
                if (files != null) {
                    for (int i = 0; i < files.length; i++) {
                        indexDocs(writer, new File(file, files[i]));
                    }
                }
            } else {
                System.out.println("adding " + file);
                try {
                    writer.addDocument(FileDocument.Document(file));
                }
                // at least on windows, some temporary files raise this exception with an "access denied" message
                // checking if the file can be read doesn't help
                catch (FileNotFoundException fnfe) {
                    ;
                }
            }
        }
    }

}
